What makes Senlin Ascends work so well is a combination of literary ambition - Bancroft's prose is evocative, exciting and occasionally beautiful - with a relentless pace. Each location is painted in rich detail, each fulfilling a function that Senlin tries to grasp (and, late in the novel, manages to do so in an intriguing moment of revelation about the tower's purpose) and each being compelling enough for entire novels to be set there. New Babel is a collection of docks and markets where people toil in labour. The Baths is a vast spa resort where deadly politics play out and Senlin is blackmailed into becoming an art robber. The Parlour is a bizarre place where guests have to take part in insane plays for the amusement of its rulers.

The Basement is a place of squalour and robbery.

Each ringdom is an impressive feat of worldbuilding, complete with its own rulers, function and cast of characters. In the course of this first novel, Senlin only ascends the lower four (of over forty) ringdoms of the tower. At key moments he realises the danger of what he is becoming and resolves to find his wife and escape before the tower batters him down from the man of integrity he used to be. Initially he proceeds with optimism and reason, but as he suffers repeated setbacks he becomes more willing to manipulate and deceive people to achieve his ends. He ventures into the miles-wide, miles-tall tower in search of help, only to find most people indifferent to his plight and out to rob or enslave him. Senlin Ascends is the story of a man who visits the Tower of Babel - which may or may not be 'our' mythological tower - on honeymoon only to lose his wife.

It's quite possibly the most striking debut work of speculative fiction published in the last decade. It's what you'd get if China Mieville and Christopher Priest collaborated on a novel and both brought their A-game, and it was then adapted for film by Studio Ghibli. It's a black comedy of manners, a dashing adventure, and a devastating deconstruction of people, places and tropes. It's a science fiction novel set inside a Big Dumb Object created by peoples unknown for scientific purposes (.perhaps?). It's a character-focused slice of the New Weird. It's a steampunk romance with airships and sky-pirates. This is fantasy, but not quite as you may know it. Senlin Ascends is the first novel in a trilogy called The Books of Babel, followed by Arm of the Sphinx (out now) and The Hod King (working title, due next year).

Senlin ascends series